I doubt it. Compared to a fixed tower wind turbine you have hull drag losses, water turbine losses, and the problem of where to put the power since you won't have cables to shore.
Some cruising sailors do use systems like this to generate their own power when under way.
Agreed. There was a link here at HN sometimes to an article about a ship with wind turbines going to see and returning with stored hydrogen as an Energy source which I thought was a good idea, if the economics eventually make it viable.
I was thinking of how many tons and how big the sails were on mast ships. If there was a design of a much lighter and smaller hulled ship ( catamarans have less drag ), and a much larger mast assembly, seemingly, it could power a decent sized generator with some force.
Power could be stored onboard and transfered via a cable-connected, station out at sea.
Some cruising sailors do use systems like this to generate their own power when under way.